Single powder photographic developers having improved stability to high temperatures



J Willia au ust, T5. 195a entit s Patented Jan. 19, 1954 orca's HAVING IMPROVED 'ro men TEMPERATURES Donald J. Kridel, Frederica. Bean, and William J. s. Rocheste "man Kodakfiompany,

1 poration of New Jersey momma applicati n une 26,1952,

Serial No. 295,833

This invention relatesto single powder photographic developers, and more pa1"tiiiularly" to single owder developers containing stabilizing materials which impart improved stabilityto the single powder developer at relatively high temperatures. g

Single powder developer mixtures may contain anorganic developer component or mixtures of such components including monomethylparaminophenol sulfate (Elon or motel), hydroquinone, p-ammophenolhydrochloride; -aminophenol sulfate, pyrogallol,w parahydroxyphenyl glycine, catechol, diaminophenol hydrochloride,

and others, with an alkaline component, a stabilizing component, an oxidizing preventer and an anti-fogging component. The alkali com'- ponent may be'the stable hydrate of an alkali carbonate, a desiccated alkali carbonate, an alkali metaboratc, or an alkali sulfit'ei Generally the stable alkali carbonate monohydrate is preierred. The oxidation. preventing component may be an alkali sulfite, and the anti-fogging component maybe potassiumbromidev or iodide. Stabilizing components for such a single powder developer are disclosedin Patent 2,384,592 of September 11, 1945, and include maleic an+ hydride, salicylic acid; alkali metabisul'fite, benzoic anhydride, orthoben zoic sulfimide phthalimide, and phthalic anhydride. The latter has outstanding stabilizing properties in the presencev ofeither sodium carbonate or borax and has been employed considerably more than the other stabilizers mentioned in that patent.

Phthalic anhydride-l ras been employed most successfully in developer compositions having. as the alkali component either sodium carbonate or sodium sulfite, or mixtures thereoti Less success has been attained in the case of the important class of developers containing sodium metaborate as an alkali ingredient, possibly the greatest disadvantage of employing phtl'ialic anhydride in single powder developer' 'miXtures,

which contain alkali carbonates and sulfite, is that phthalic anhydr-ide, when used alone in suf- .lficient amounts for stabilizin purposes, may react due in part to temperature effects with these basic substances and form gas under sufiflcient pressure to distend the hermetically sealed can in which the developer powder ispackaged, and

cause a portion of the powder to be ejected I with "some io'rceas the package is peiied. k

tion in the of t asse ses. a

- peters, g n No! 210,285; tiled February alkali carbonate hydrate N. assi'gno'rs to East-l Rochester, N; Y., acm

for Slngle Powder l hotographic Developers an advantageous new stabilizer, bone anhydride, tor single powder developers is. disclosed and claimed. Boric anhydride does netnave the disadvantages peculiar to: pnthalic anhydride. It ap ears that boric anhydrlde being muchless acid than phthalic anhydride does not react as easily as phthali'c anhydrid'e with alkali carbonates or alkali sul-fites such as sodium carbonate and sodium sulfite. In this respect it is noted that the pilot the phthalic acid derived from phth'alic anhydride is about while the pH of boric acid derived from bone anhydride is about 5.4 at 31% concentrations. Boric anhydride is admirably suited as a stabilizer and has the characteristics required for a stabilizer. It is acidic, relatively colorless, odorless, and stable and has not use e'terious action photographically.v

Boric anhydri'de is'pa'rticularly suited for use in the single powder photographicdeveloper mix-.- ture of either the stable hydrate of an alkali car.- bona'te or also a desiccated alkali carbonatet The I appears to be more stable in the-presence of an organic developer than a eom arable'quantity of the con'espondi'n'g desiccated 'alkali carbonate.

stated in the Rogers application, samples of mixtures of single powder developers containing borie anhydride have been kept in hermetically sealed cans at 120 F. for prolonged periods and v were found to be unimpaired in'de'veloping propi stab ins 5 temperatures might be encountered I temperature erties and to give a solution comparable in color to solutions prepared from such chemicals not previously mixed.

It, however, has been found on further investigation that in tropical countries, and the same in poorly ventilated storage places in temperate climates, the temperature may rise above If the single powder photographic developers which are stabilized with borije anhydride, as described in the Rogers application',are subiectedto prolonged temperatures above 12 interaction of the comp nen s of powd r occurs. A very slig t arkening or brownins of t powders may be noted after two monthsat such raised temperatures,

It, herefore, became apparent that a. singl powder developer having characteristics which would prevent decomposition oi the powder at to and a ov izr 1! was needed certain g ographic Ut ties. ,7 v

, t, therefore, 01 thapresent invention to PlQv'ide an improved stabilizing agent for single powder developer's.

F. a sli ht amount o o the sin l 6 Another object of the invention is to provide an improved stabilizing agent for single powder developers which will prevent decomposition of the developer at temperatures up to 130 F.

A further object of the invention is to provide an improved stabilizing agent which makes possible the production of single powder developers having improved stabilizing characteristics 'containing as the alkali ingredient, sodium metaborate.

Still another object is te -providean improved stabilizing agent for single powder developers which has superior characteristics as respects phthalic anhydride or boric anhydride as stabilizing agents.

Other objects will appear hereinafter.

In accordance with the invention we have dis- Grams Grams Elon 2. 2 2. 2 Hydroquinone 8. 8 8. 8

7 Sodium sulfite (desiccated) 96. 90. 0

' Sodium carbonate monohydrate 56.0 56.0 Potassium bromide 5.0 5.0 Boric auhydrlde 1. 7 1.7 Phthalic anhydride 0. 33 None covered that this high temperature keeping of single powder developers which contain both organic developer components and basic components may be attained by employing as the stabilizerboric anhydride and relatively small quantitie of phthalic anhydride.

Whereas in the single powder developer mixtures described in the Rogers application, there .are normally employed concentrations of boric anhydride of 0.5 to 3% based on the total formula weight, the additional amount of phthalic anhydride added to these formulas to improve .-high temperature keeping is in therange of 0.05

to 0.3%. W have found that a concentration of 0.5% phthalic anhydride should not be exceeded because of the possibility of generating pressure in the sealed cans due to formation of carbon dioxide and sulfur dioxide formation.

T-he boric anhydride may contain moisture up 0t 35% by weight and Where the term boric anhydride is mentioned in this specification, boric anhydride with a moisture content within this range is meant.

The ingredients of a single powder developer composition may therefore consist of an organic 'developing agent, such as monomethyl paraminophenol sulfate, hydroquinone, p aminophenol hydrochloride, p-aminophenol sulfate, pyrogallol,

.p-hydroxyphenyl glycine, catechol, diaminophe- 'nol hydrochloride, and suitable mixtures thereof, a stable alkali carbonate, such as sodium carbonate monohydrate, boric anhydride and a relatively small amount of phthalic' anhydride and may contain the other well known ingredients normally present infla developer, such as sodium sulfite and potassium bromide, the normal and known function of the alkali sulfite being that of preservation, lessening the oxidation in solution of the organic developing agent, while the known function of potassium bromide is that of are'strainer particularly inhibiting fog formar tion in the development of the silver image.

In compounding the single powder developer mixture, one may proceed by first mixing th required amount of boric anhydride and phthalic anhydride with the basic component. The developing agent is then added and incorporated. therewith and then the remaining ingredients may be incorporated. However, one can mix all the ingredients together at the same time, if desired.

'i [.Th following examples will serve further to illustrate developer mixtureswithin the scope of the. invention and .willalso indicate theproporftionate quantities in which the respective components can be mixed together in a dry form to make up such single powder photographic "developer mixtures.

When packaged in a sealed can and kept for 96 hours at 130 F. sample A was white showing that no reaction or deterioration took place, whereas sample B similarly packaged and heated was discolored. This clearly shows that the phthalic anhydride raises the upper heat resisting range of the mixture.

Example 2 A B O Grams Grams Grams E1011 2.0 2.0 2.0 Hydroquinone 8. 0 8. 0 8. 0 Sodium sulfite (desiccated) 90. 0 90. 0 90. 0 Sodium carbonate monohydrate 52. 5 52. 5 52. 5 Potassium bromide 5.0 5.0 5.0 Bcric anhydride 1.6 1.6 1.6 Phthalic anhydride 0. 16 0. 08

After scaling in separate cans and heated for 5 days at -130 F. samples A and B were white whereas sample C showed slight discoloration.

After sealing in individual cans and heated for 5 days at 125130'F. samples A and B were white whereas sample C was appreciably discolored.

Example 4 Grams Grams Elon 1. 5 1. 5 .Hydroquinone. 6. 0 G. 0 Sodium sulfite (de ccate 22.5 22. 5 Scdium carbonate monohydrate 17. 0 17.0 Potassium bromide 1.5 1. 5 Bcric anhydride 0. 5 0. 5 Phthalic anhydride 0. 05

After scaling in a can followed by incubation at F. sample A was white whereas sample 13 had noticeable discoloration.

Example 5 Grams Elon 2.5 Sodium sulfite (desiccated) 30.0 Hydroquinone, 2.5 "Sodium metaborate (10% H2O) 10.5 Potassium bromide 0.5 Borio anhydride 0.5 Phthalic anhydride 0.05

No discoloration was noted after this formula was placed in a sealed can and incubated at 125 ,F.

Our inventionthus provides single-p'owderdevelopers which are stable above 125 F. and hence they can be employed in areas in which extreme temperatures are encountered.

' We claim:

1. A stable single-powder photographic developer composition containing an organic silver halide developer, 0.5 to 3% by weight of a stabilizing agent comprising boric anhydride having a moisture content not exceeding approximately 35% by weight, 0.05 to 0.3% by weight of a stabilizing agent comprising phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from 120-130 F. and a soluble stable, and photographically compatible basic ingredient selected from the group consisting of alkali borates, sulfites and carbonates.

2. A stable single-powder photographic developer composition containing an organic silver ha lide developer, sodium carbonate monohydrate, 0.5 to 3% by weight of boric anhydride containing less than 35% moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from 120-130 F.

3. A stable single-powder photographic developer composition containing an organic silver halide developer, an alkali sulfite, 0.5 to 3% by weight of boric anhydride containing less than G by Weight of moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adaptedto prevent decomposition of the developer when exposed to temperatures from -l30 F.

4. A stable singlepowder photographic developer containing an organic silver halide developer, an anhydrous alkali carbonate, an alkali 'sulfite, 0.5 to 3% by weight of boric' anhydride containing less than 35% by weight of free moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from 120- F.

Y 5. A stable single powder photographic developer composition containing an organic silver halide developer, desiccated sodium sulfite, 0.5 to 3% by weight of boric anhydride con,- taining less than 35% by weight of moisture, and 0.05 to 0.3% by weight of phthalic anhydride, said mixture of stabilizing agents adapted to prevent decomposition of the developer when exposed to temperatures from'120-13'0 F.

DONALD J. KRIDEL. FREDERIC R. BEAN. WILLIAM J. ROGERS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,384,592 Bean Sept. 11, 1945 2,606,118 Rogers Aug. 5, 1952 

1. A STABLE SINGLE-POWDER PHOTOGRAPHIC DEVELOPER COMPOSITION CONTAINING AN ORGANIC SILVER HALID DEVELOPER, 0.5 TO 3% BY WEIGHT OF A STABILIZING AGENT COMPRISING BORIC ANHYDRIDE HAVING A MOISTURE CONTENT NOT EXCEEDING APPROXIMATELY 35% BY WEIGHT, 0.05 TO 0.3% BY WEIGHT OF A STABILIZING AGENT COMPRISING PHTHALIC ANHYDRIDE, SAID MIXTURE OF STABILIZING AGENTS ADAPTED TO PREVENT DECOMPOSITION OF THE DEVELOPER WHEN EXPOSED TO TEMPERATURES FROM 120-130* F. AND A SOLUBLE STABLE, AND PHOTOGRAPHICALLY COMPATIBLE BASIC INGREDIENT SELECTED FROM THE GROUP CONSISTING OF ALKALI BORATES, SULFITES AND CARBONATES. 